Polymorphic electro-optic displays

ABSTRACT

Described herein is a polymorphic display, which is a unitary apparatus constructed such that a wide variety of electro-optic functions are enabled. The polymorphic display, even when having multiple pixels, enables sharing of selected structures among the pixels. In a multi-pixel construction, there is a set of pixels in the display that exhibit one set of operable properties, such as particular stability, sequencing, and switching properties, and another set of pixels that are different from the first set. That is, they have different stability, sequencing, or switching properties. In such a way, a highly flexible polymorphic display may be construed to satisfy a wide range of display needs.

RELATED APPLICATIONS

This application claims priority to U.S. provisional patent applicationNo. 62/723,835, filed Aug. 28, 2018, and entitled “Novel DisplayDevice.” This application is also a continuation-in-part application toU.S. patent application Ser. No. 15/958,813, filed Apr. 20, 2018, andentitled “Polymorphic electro-optic Displays, which is a continuation inpart application to U.S. patent application Ser. No. 15/890,312, filedFeb. 6, 2018, and entitled “Polymorphic Electro-Optic Displays,” whichclaims priority to U.S. provisional patent application No. 62/478,216,filed Mar. 29, 2017 and entitled “Hybrid Displays,” and to U.S.provisional patent application No. 62/455,502, filed Feb. 6, 2017, andentitled “Hybrid Displays,” both of which are incorporated herein byreference. This application is related to U.S. patent application Ser.No. 13/002,275, filed Dec. 30, 2010, now issued as U.S. Pat. No.9,030,724; and to U.S. patent application Ser. No. 14/797,141, filedJul. 12, 2015, both of are incorporated herein by reference.

FIELD OF THE INVENTION

The field of the invention is manufacture and use of electronic displayscomprised of electro-optic pixels.

BACKGROUND

The internet of things (IoT) and other emerging markets for inexpensive,and often disposable, intelligent electronic devices are creating demandfor smaller, thinner, often flexible, ruggedized, and fit-for-purposeelectro-optic displays. Currently known display devices are constructedof multiple pixels, that when viewed together, display a message orsymbol to the user. The pixels of these conventional displays, are ofthe same type. A mono-stable display for example will have onlymono-stable pixels while a bi-stable display will have only twostable-states, electrically switchable pixels. The pixels of common (noncholesteric) LCDs are mono-stable, but each is the same as the others.The pixels of three-color electrophoretic displays are multi-stable,that is they are stable in three states, but the pixels themselves areall the same.

SUMMARY

Described herein is a polymorphic display, which is a unitary apparatusconstructed such that a wide variety of electro-optic functions areenabled. The polymorphic display, even when having multiple pixels,enables sharing of selected structures among the pixels. In amulti-pixel construction, there is a set of pixels in the display thatexhibit one set of operable properties, such as particular stability,sequencing, and switching properties, and another set of pixels that aredifferent from the first set. That is, they have different stability,sequencing, or switching properties. In such a way, a highly flexiblepolymorphic display may be construed to satisfy a wide range of displayneed.

The ability to create different, fit-for-purpose transition sequences isan important benefit of polymorphic displays and as described below, ofpolymorphic pixels. Of particular benefit of the property of transitionsequencing is the ability to selectively and dynamically determine andeffect a transition sequence, and therefore the operable properties of apolymorphic pixel or polymorphic display, responsive to differentelectrical signals. And further, where the electrical signals aregenerated responsive to various conditions, events and actions etc.,such as those common to intelligent display devices described laterherein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing operable states and corresponding opticalstates for a display in accordance with the present invention.

FIG. 2 is a diagram showing operable states and corresponding opticalstates for a display in accordance with the present invention.

FIG. 3 is a diagram showing operable states and corresponding opticalstates for a display in accordance with the present invention.

FIG. 4 is a diagram showing operable states and corresponding opticalstates for a display in accordance with the present invention.

FIG. 5A is a block representative of a display in accordance with thepresent invention.

FIG. 5B is a block representative of a display in accordance with thepresent invention.

FIG. 6A is a block representative of a display in accordance with thepresent invention.

FIG. 6B is a block representative of a display in accordance with thepresent invention.

FIG. 6C is a block representative of a display in accordance with thepresent invention.

FIG. 6D is a block representative of a display in accordance with thepresent invention.

FIG. 6E is a block representative of a display in accordance with thepresent invention.

FIG. 7 is a diagram showing operable states and corresponding opticalstates for a display in accordance with the present invention.

FIG. 8 is a diagram showing operable states and corresponding opticalstates for a display in accordance with the present invention.

FIG. 9A is a block representative of a display in accordance with thepresent invention.

FIG. 9B and FIC. 9C are block representations of displays in accordancewith the present invention.

FIG. 10A is a block representative of a display in accordance with thepresent invention.

FIG. 10B is a block representative of a display in accordance with thepresent invention.

FIG. 11 is a legend to the stippling used in the Figures.

FIG. 12A is a block representative of a display in accordance with thepresent invention.

FIG. 12B is a block representative of a display in accordance with thepresent invention.

FIG. 12C is a block representative of a display in accordance with thepresent invention.

FIG. 12D is a block representative of a display in accordance with thepresent invention.

FIG. 13 is a diagram showing operable states and corresponding opticalstates for a display in accordance with the present invention.

FIG. 14 is a block representative of a display in accordance with thepresent invention.

FIG. 15A is a block representative of a display in accordance with thepresent invention.

FIG. 15B is a block representative of a display in accordance with thepresent invention.

FIG. 15C is a block representative of a display in accordance with thepresent invention.

FIG. 15D is a block representative of a display in accordance with thepresent invention.

FIG. 15E is a block representative of a display in accordance with thepresent invention.

FIG. 16A is a block representative of a display in accordance with thepresent invention.

FIG. 16B is a block representative of a display in accordance with thepresent invention.

FIG. 16C is a block representative of a display in accordance with thepresent invention.

DESCRIPTION

Described herein are polymorphic electro-optic displays (“polymorphicdisplays”). Polymorphic displays are unitary apparatus having multipleoperable properties. Of particular interest are the operable properties,individually and in combination, of stability, switching and transitionsequencing.

-   -   Mono-stable, bi-stable, multi-stable, permanent    -   Electrically switchable, self-switchable, non-switchable    -   Reversible, irreversible, repeatable

Polymorphic displays may be constructed to have multiple types ofelectro-optic display pixels (“pixels”), each type having differentoperable properties. Polymorphic displays may also be constructed with“polymorphic pixels” described herein, that individually have multipleoperable properties, and are independently operable to produce differentoperating states.

The operable properties of a polymorphic display's pixels determine itspossible operating states, e.g. whether the pixel is stable or volatile,switchable or self-switching from one state to another or not switchableonce in a previously switched to state, or the transition sequence isforward, forward-only (irreversible), reverse, or branching, or acombination thereof.

The optical state of a polymorphic display's pixel corresponds to thepixel's operating state[s] according to the pixel's optical properties.For example, one polymorphic display pixel may be white in a stable,first state, and dark blue in a volatile, second state, and red in athird, stable state.

It is important to note that the pixels of conventional electro-opticdisplays, are of the same type. A mono-stable display for example willhave only mono-stable pixels while a bi-stable display will have onlytwo stable, electrically switchable pixels. The pixels of common (noncholesteric) LCDs are mono-stable, but each is the same as the others.The pixels of three-color electrophoretic displays are multi-stable,that is they are stable in three states, but the pixels themselves areall the same.

Pixels have at least two optical states according to their opticalproperties that typically include color perceptible to the human eye.For a passive (non-emissive) display pixel the optical state of thepixel may in general be determined by the resulting opticalreflectivity, transmission, or polarization, of the pixel (at a specificwavelength or wavelength range of the illuminating source), whereas foran emissive display it may be determined by the intensity, polarizationand spectral composition of the emitted light. In the case of displaysintended for machine reading, the optical state of the pixel may, e.g.,be determined by a pseudo-color in the sense of a change in reflectivityat electromagnetic wavelengths outside the human visible range.

Pixels may be of various sizes, shapes, patterns and configured to standalone or in groups (e.g. as segments to create alphanumeric characters,or RGB super pixels). Pixels typically comprise an electro-optic layerwith electrodes either in direct contact with, or in close proximity to,the electro-optic layer. Depending on desired operable properties of thedisplay pixels, the composition of their electro-optic layers maycomprise for example, electrochromic materials, liquid crystals,electrophoretic particles, electrowetting fluids, electro-liquid powdermaterials, etc.

Display pixels may be categorized according to the operable propertiesassociated with them being mono-stable, bi-stable and multi-stable, andpolymorphic. Descriptions of the pixel types are described in generalbelow, and later in detail.

Mono-Stable Pixels

Mono-stable pixels have one, stable operating state (and correspondingoptical state) and a second, volatile operating state (and correspondingoptical state). Mono-stable pixels also have the stability operableproperties of being reversible and self-switching. That is, theyautomatically, or “self”, switch from their volatile operating state toback their stable, first operating state when power to the pixel isterminated (or drops below a threshold necessary to maintain the state).

A mono-stable pixel's first, operating state is stable without power.When an electrical switching signal is applied to a mono-stable pixel,the pixel transitions from a stable, first operating state to avolatile, second, operating state. The volatile operating state ismaintained as long as a maintenance signal is applied to the pixel. Whenthe maintenance signal is terminated (for whatever reason) the pixelself-switches from the second operating state back to the first, stableoperating state. Examples of mono-stable displays comprised ofmono-stable pixels are common LCDs (liquid crystal displays), EPDs(electrophoretic and ECDs (electrochromic displays), and LEDs(light-emitting diodes) and OLEDs (organic light-emitting diodes).

The operable states and corresponding optical states of an exemplarymono-stable pixel 100 are illustrated in FIG. 1. In this example, thefirst operating state 111 is stable and switchable, and itscorresponding optical state (color) is white. Note that FIG. 11 presentsa legend for colors-to-patterns, shapes and symbols used in the otherfigures. The second operating state 113 is volatile, self-switchable(reversible), and its corresponding optical state is purple. Whenself-switched (power is terminated to the pixel) the pixel transitionsback (reverses) to the stable, first operating state 111, andcorresponding optical state (white).

FIG. 1 Also illustrates a mono-stable pixel 200 similar to mono-stablepixel 100. Mono-stable pixel 200 however has an optional secondvolatile, self-switching operating state 216, and a corresponding blueoptical state. As with the first volatile, self-switching operatingstate of pixel 100, pixel 200 self-switches from the optional secondvolatile operating state 216 to the stable, first operating state 212when power to the pixel is terminated or disrupted.

The pixel 200 has the transition sequence property (described later) ofbranching, that is the property whereby the transition sequence dependson the current state of the pixel and the switching signal. In thisexample, a first switching signal transitions the pixel from its stable,switchable first operating state 212 to a first volatile,self-switchable operable state 214, and a corresponding optical state,in this case purple. After the pixel 200 has self-switched to thestable, switchable first operating state 212, a second switching signal(different than the first) transitions the pixel to a second volatile,self-switchable operable state 216, and corresponding optical state, inthis case blue.

Bi-Stable and Multi-Stable Pixels

Bi-stable pixels have two stable operating states. Switching between thetwo, stable operating states is accomplished with an electricalswitching signal. Once switched, the operating state (and thecorresponding optical state) persists when the power is terminated(without a maintenance signal).

Bi-stable pixels may be reversible (e.g. EPDs, conventional ECDs,cholesteric, ferroelectric or zenithal bistable LCDs) or irreversible(as described in U.S. Pat. No. 9,030,724 Flexible and PrintableElectrooptic Devices). Conventional bi-stable pixels are electricallyswitched and are not self-switching (but always switchable). Some pixelscharacterized as bi-stable however, have limited persistence in one orthe other optical states. In other words, some bi-stable pixels areself-switching over time. Such pixels, may therefore be more accuratelyconsidered mono-stable with limited persistence in the second operatingstate (the first being unpowered).

The operable states and corresponding optical states of exemplarybi-stable pixels are illustrated in FIG. 2. Pixel 300 has a firstoperating state 310 that is stable and switchable, and a correspondingoptical state (color) that is white. The second operating state 320 isalso stable and switchable (and reversible), and its correspondingoptical state is red. Note that a maintenance signal is not required forthe pixel to remain in the second operating state once switched from thefirst operating state. Note further that the second operating state isnot self-switching, and a switching signal is required to switch fromthe second, stable operating state, and corresponding optical state,back to the first stable operating state.

Pixel 400 is also bi-stable however unlike the pixel 300 in the previousexample, once switched from the first stable, switchable operable state430 to the second, stable operable state 440, pixel 400 isnon-switchable (not switchable or self-switching). In the secondoperable state, pixel 400 is irreversible and permanent. It cannot beswitched (transitioned from the second operable state to the first) andhas the stability property of being non-switchable and a transitionsequence property of being irreversible.

In addition to bi-stable pixels there are a few types of multi-stablepixels, typically having three, stable states. One example are thepixels in three-color, electrophoretic displays. Each pixel containsthree distinct particle types (e.g., pigment or dye particle)corresponding to different colors. Note however that as withconventional mono-stable and bi-stable displays, the operable propertiesof the pixels are the same.

The operable states of a multi-state pixel 500 are illustrated in FIG.3. In the first operating state 510 pixel 500 is stable, switchable(forward-only, irreversibly) with a corresponding optical state (color)that is white. The second operating state 520 is also stable andswitchable, with a corresponding optical state (color) that is blue. Inthe second operating state however, the transition sequence isforward-only to the third operating state 530. It cannot be switched tothe first stable operating state from the second stable operating state.The third operating state 530 is also stable and switchable, and has acorresponding optical state (color) that is red. Unlike the pixel whenin the second operating state 520, when the pixel is in the third stableoperating state 530, it can be switched back to its previous operablestate 520. And further, unlike the transition from the first operatingstate to the second, the transitions from the second operating state tothe third operating state, and the reverse, are repeatable. Thetransition sequence therefore comprises three inter-state transitions(described later), one which is forward-only and irreversible, and twothat are forward-only, reversible and repeatable.

Polymorphic Pixels

Polymorphic pixels may be constructed to have various combinations ofoperable properties. Polymorphic pixels have at least two stableoperating states, an unpowered, first state and at least one otherstable state which may for example be irreversible and permanent aspreviously described. They also have one or more volatile operatingstates.

FIG. 4 illustrates the operable states of a polymorphic pixel 600. Thepixel has two stable operating states 610 and 630 and one volatileoperating state 620. Pixel 600 also has two transition sequence branches601 and 602. The transition sequence branch is selected with a switchingsignal that determines the next operating state. Branch 601 comprises afirst operating state 620 that is stable, switchable with acorresponding optical state (color) that is white. Branch 601 alsocomprises a second operating state 620 that is volatile, self-switchingwith a corresponding optical state (color) that is red. Upon terminationor disruption of a maintenance signal, pixel 600 will self-switch andtransition from the volatile, self-switching state 620 to the previousoperating state 620. Branch 601 comprises two inter-state transitionswhich are both reversible and repeatable, until and unless, transitionsequence branch 602 is selected with a switching signal that transitionsto operating state 630.

Branch 602 comprises the same first operating state 620 as branch 601,however unlike branch 601 it has a second operating state 630 that isirreversible and permanent. Because operating state 630 is irreversibleand permanent, branch 602 comprises only one inter-state transition, aforward, irreversible transition from operating state 620 to operatingstate 630. Once switched (transitioned) along branch 602 to operatingstate 630 by an appropriate switching signal, the pixel is no longerswitchable (non-switchable). In total the transition sequence propertyfor pixel 600 includes three inter-state transitions (two repeatable,and one irreversible).

FIG. 7 illustrates the operable states of another exemplary polymorphicpixel 900. The pixel in this case has two stable operating states 905and 908 (and two corresponding optical states, white and blackrespectively). Pixel 900 also has two volatile operating states 906 and910 (and two corresponding optical states, red and purple respectively).In total, polymorphic pixel 900 has four possible operating states andcorresponding optical states (red, white, black and purple). Unlikepolymorphic pixel 600 polymorphic pixel 900 has a transition sequencecomprising two branches 902 and 903. The branch selected depends on theswitching signals and the prior operating states of the pixel. In thefirst operating state 905 pixel 900 is stable, switchable with acorresponding optical state (color) that is white. The transitionsequence along branch 902 consists of a stable, switchable firstoperating state and a volatile, self-switching second operating state.Branch 902 is reversible and repeatable until the pixel is operablyswitched to branch 903.

The transition sequence along branch 903 consists of the same firstoperating state 905, stable, switchable with a corresponding opticalstate (color) that is white. Branch 903 also comprises a stable,switchable second operating state 908 with a corresponding optical state(color) that is black. Once switched from the first operating state 905to the second operating state 908, the pixel cannot transition back tooperating state 905. The transition sequence from 905 to 908 is notreversible (irreversible) and is therefore not repeatable. Fromoperating state 908 the transition sequence is only forward to operatingstate 910. The third operating state 910 along branch 903 is volatile,self-switching with a corresponding optical state (color) of purple. Theinter-state transitions between operating states 908 and 910 aretherefore reversible and repeatable.

The transition sequence along the entire branch 903 from operating state905 to operating state 910 includes both forward, irreversibletransitions and forward, reversible transitions. Note that the once thepolymorphic pixel 900 is switched and transitions to branch 903 (fromoperating state 905 to operating 908) it cannot be switched, transitionto branch 902 and operating state 908. The polymorphic pixel 900 canhowever effect different operating states along branch 902 and thenswitch be switched, transition to branch 903.

Transition Sequencing

An operable property of pixels is transition sequencing, that is, theproperty of being able to transition between multiple, differentoperating states in sequences that include forward, forward-only(irreversible), reverse (reversible), repeatable and non-repeatable andcombinations thereof. A transition sequence is comprised of inter-statetransitions, that is transitions between two consecutive operable statesof a pixel. Exemplary transition sequences are described below andillustrated in embodiments 100, 200, 300, 400, 500, 600, 900, and 1000.Transition sequencing also includes branching. Branching is the propertyof being able generate different sequences of inter-state transitionsfrom a particular operable state of the pixel. A branch is created byeffecting one of a plurality of transitions according to differentelectrical signals. Embodiment 200 illustrates simple transitionsequence including branching for a mono-stable pixel. Of particularinterest are complex transitional sequences for polymorphic pixelsincluding branching properties such as those illustrated in embodiments900 and 1000.

Note that the conventional terms reversible and irreversible imply theability, or lack of ability, of a pixel to reverse or switch back to aprevious operating state. Polymorphic displays introduce the ability toelectrically switch (with a switching signal) or self-switch (byterminating a maintenance signal) the operating state from one toanother operating state that is other than the previous one. Note aswell, that the transition sequencing property of polymorphic pixels canbe produced using a variety of different polymers and combinations ofthem, e.g. with mixtures combining more than one type, or depositingmore than one layer of them within the polymorphic pixel.

The ability to create different, fit-for-purpose transition sequences isan important benefit of polymorphic displays and as described below, ofpolymorphic pixels. Of particular benefit of the property of transitionsequencing is the ability to selectively and dynamically determine andeffect a transition sequence, and therefore the operable properties of apolymorphic pixel or polymorphic display, responsive to differentelectrical signals. And further, where the electrical signals aregenerated responsive to various conditions, events and actions etc.,such as those common to intelligent display devices described laterherein.

Polymorphic Displays

In its simplest embodiment, a polymorphic display is an electro-opticdisplay comprising a single polymorphic pixel. More typically however, apolymorphic display is a unitary apparatus constructed having at leasttwo pixels, the pixels having at least some of the following elements incommon: structure, materials, circuitry, and optionally a display driverIC. As previously described, the display pixels may be of differenttypes according to their operable properties.

The structure of a polymorphic display determines its physical form. Thestructure comprises for example, substrates, spacers, matrices,separators, spacers, barriers, sealants, transparent/viewing surfaces(e.g. ‘windows’) etc. typically, but not always, organized in layersthat preferably lend themselves to high volume manufacturing processes(e.g., printing, spray casting, roll-to-roll manufacturing etc.). Apolymorphic display's structure complements that of the electro-opticmaterials, other materials (e.g. adhesives) and electrical circuitry(including electrodes). For example, the electro-optic layers ofdifferent pixel types (e.g. electrochromics, LCDs, EPDs etc.) are oftenconstructed with materials that are fluid or semi-solid and thereforethat depend on various structures to hold them. And importantly, toreliably couple to the electrical circuitry.

A polymorphic display's electro-optic layer, and the pixels of whichthey are made, may share common materials. Such materials may forexample be constructed as a single, continuous layer across multiplepixels, such as the electrolyte illustrated in FIGS. 5A and 10A.Alternatively, a material (e.g. the electro-optic material 710 of FIG.5A and 1310 and 1320 of FIG. 10A) may be common to some but not all thepixels, and may be constructed as discrete, spatially separated elementswithin same physical layer (or the same manufacturing process). Suchpatterning advantageously allowing for other common materials to beinterspersed among them.

As noted previously, a pixel comprises an electro-optic layer withelectrodes either in direct contact with, or in close proximity to, theelectro-optic layer. The electrodes are configured for applyingelectrical signals to the pixels individually or in groups and aretypically formed on common structure (e.g. flexible substrates orlayers). The electrodes may be configured in various ways includingvertical (e.g. on the top and bottom surfaces of an electro-optic layer,interdigitated (both electrodes are on the same layer), or combinationsof both. Typically, but not always, the electrodes on the side or sidesof the electro-optic layer facing the viewing surface or surfaces, aretransparent e.g. ITO or transparent, conductive silver-inks patterned onPET.

The pixel electrodes may be exposed for connection to circuitry ofanother device such as an intelligent display device describe herein.The electrodes may also be coupled to additional circuitry andcomponents (e.g. display driver IC, backplane etc.) constructed as partof the polymorphic display apparatus (e.g. using common structure), forpixel addressing, signal management/noise reduction, visibleverification (such as that described in U.S. patent application Ser. No.14/927,098 Symbol Verification for an Intelligent Label Device, and Ser.No. 15/368,622 Optically Determining Messages on a Display) etc.

As illustrated in FIGS. 5A, 6A and 9A, exemplary display pixels 700, 800and 1100 are configured with electrodes on the surfaces of theelectro-optic layer (e.g. front and back). The electrodes however may beconfigured as interdigitated pairs located on a single surface. This mayallow for simpler, lower cost manufacture, thinner devices, and in somecases may advantageously enable different operable and opticalproperties. And in some designs, interdigitated electrodes may workcooperatively with conventional surface electrodes. FIGS. 10A and 10B isan exemplary four-pixel structure employing interdigitated electrodesand different, patterned material layers to create pixels havingdifferent operable (and associated optical) properties. The viewingperspective is from the back of the structure. Note that theillustrations are intended only to focus on certain elements of apolymorphic display and not completed devices. Note further, the commonmaterial layers of which some are patterned and some continuous acrossthe pixels.

The first layer 1200 of the four-pixel structure (viewed from the back)is a transparent substrate 1230 having interdigitated electrode 1220 andfour companion electrodes 1210 (of which only one is numbered).Electrode 1220 is common to the four companion electrodes, all of whichare collectively part of the display circuitry. Each of theinterdigitated patterns are the foundation for four individual pixels.Structure 1300 shows layer 1200 with printed (or otherwise deposited)polymer 1310 and a different polymer 1320. Polymer 1310 spans two pairsof interdigitated electrodes so the corresponding pixels will have thesame operable properties. Polymer 1310 covers a single electrode pairand the corresponding pixel will have operable properties different fromthe other three. Structure 1400 shows layer 1300 with a printed (orotherwise deposited) opaque electrolyte 1410. Electrolyte 1410 is anopaque EC mix. In this example, all three of the pixels with polymerlayers will have the properties of being volatile, self-switchable. Thefourth interdigitated electrode pair (the one without a polymer layer)will have the properties of being stable, switchable, irreversible andpermanent. Structure 1500 is the same as structure 1400 with atransparent EC mix instead of the opaque EC mix 1410. This integrated,process friendly structure comprises four separately operable pixels,three having the properties of being volatile, self-switching (two ofone type, and one of another) and one having the same operableproperties of being irreversible and permanent.

Signal Protocol

A signal protocol is used by the processor to manage the differentswitching signals and maintenance signals according to the types ofpixels which comprise the polymorphic display. The signal protocolprovides the timing, duration, pattern (e.g. pulse shape, sequence),frequency, voltage or current, polarity etc. required by the processorto generate the appropriate signals.

Switching Signal

A switching signal is an electrical signal applied to a pixel forsetting the operating states of the pixel (e.g. for switching from oneoperating state to another).

Maintenance Signal

A maintenance signal is an electrical signal applied to a pixel in avolatile state (self-switching) to maintain its current operating state.The maintenance signal is often different from the switching signal thatswitched the pixel to the current volatile operating state that ismaintained by the maintenance signal.

Intelligent Display Device

An intelligence display device is an apparatus comprising a polymorphicdisplay, and some or all of electronics, a power apparatus andappropriate to the application, a communication apparatus, sensors, andactuators. An intelligent display device is typically a unitaryapparatus configured to be coupled or combined with a good or itspackaging. Often, but not always, the intelligent display device is lowcost, often disposable, low power and small in size. In someapplications, though the intelligent display device is significantlylarger and designed to present high-content messages or messages to beread by humans or machines at a distance. Exemplary configurationsinclude labels, patches, tags, smart-cards, loyalty cards, packaging,containers, seals, caps, documents, test/sensing/monitoring devices,terminals, electronic-shelf labels, free-standing displays, electronicsdevices etc.

Electronics

In addition to a polymorphic display, intelligent display deviceincludes electronic functions, for example, processor, memory,clock/timer, security, verification, communications and sensors, etc.that may be integrated into a single electronic device or implementedwith discrete components.

The electronics will also typically include display driver circuitryconfigured to store and process appropriate data and algorithms (e.g. asignal protocol), temperature compensation etc. to generate theelectricals to the polymorphic display and pixels it comprises. Thedisplay driver circuitry may be advantageously configured with theprocessor and memory or one or more separate components. And further,the display driver circuitry may be configured as part of thepolymorphic display or as part of the electronic functions of theintelligent display device, or, distributed between the two.

Power Apparatus

The intelligent display device includes one or more power apparatus forpowering the electrical functions in the intelligent label including apolymorphic display. Exemplary power apparatus include internal energystorage such as batteries or charged capacitors, wired interfacescapable of receiving electrical energy, wireless energy harvesters, or acombination thereof. The energy harvester for example, may produceelectric energy from light (e.g. solar cell), RF energy (e.g.,antenna/rectifier), thermal energy (e.g., thermopile), or shock andvibration (e.g. strain gauges, nanogenerators, MEMS devices) that theintelligent label device is subject to.

Communication Apparatus

Typically, the intelligent display device also has electronics thatenable wireless or wired communication to or from the intelligent label.Exemplary wireless communication apparatus includes those that supportWi-Fi, Bluetooth, BLE, RFID (e.g. RAIN or NFC), ZigBee and other localarea wireless networks, low power wide area (LPWN) and cellular andother wide area networks. Intelligent display devices may includesupport for portable memory chips, cards, sticks and other portablememory storage devices.

Sensors

An intelligent display device may have one or more sensors sensing theinside or outside environment (outside or inside the intelligent displaydevice), the polymorphic display or other components or systems of theintelligent display device. Exemplary sensors include a temperaturesensor, a humidity sensor, and altitude sensor, a pressure sensor, anoptical sensor, a vibration sensor (including a shock sensor), ahumidity sensor, biological or a chemical sensor (including a gassensor, a pH sensor), a magnetic sensor, a smoke sensor, a radiationsensor etc. It will be appreciated that a wide variety of sensors couldbe used depending upon the particular application.

Actuators

Depending on the application, an intelligent display device, may haveone or more actuators. Actuators activate, deactivate or otherwiseeffect control over electrical functions in the intelligent displaydevice in response to external or internal stimulus, e.g. mechanicalaction, sensor input, electrical or wireless signals etc. Actuators maybe used to activate different electrical functions at different times,e.g. when an item is shipped (the package is sealed) or when an item isreceived (the package is opened).

Actuators may also minimize power consumption, and thereby maximizingthe shelf-life/operating life of intelligent display devices havinginternal power apparatus, by activating electronics only whenappropriate to the application. Actuators, in cooperation withtimers/clocks may also be used to establish the time/date an eventoccurs.

Exemplary actuators include mechanical switches (e.g. the open or closean electrical circuit), electro-optic, electrochemical,electro-mechanical and electro-acoustic devices, wired connectors (forreceiving electrical signals), wireless receivers (for harvesting RFenergy, receiving RF signals) etc., and are described in U.S. Pat. No.9,471,862 An Intelligent Label Device and Method.

Example 1 (Polymorphic Display)

FIG. 5A shows an exemplary configuration of a polymorphic display 700comprising two pixels, each having different operable properties, inside view and front view. For illustration purposes, only two pixels areshown although it is to be understood that a polymorphic display maycomprise many such pixels. The right pixel 701 is bi-stable, having abi-stable, permanent and irreversible second operating state (such as200 in FIG. 2), whereas the left pixel 702 is mono-stable andself-switchable (such as 100 in FIG. 1).

In regard to bi-stable pixel 701, detailed embodiments of bi-stable,permanent and irreversible display devices and pixels, are disclosed inU.S. Pat. No. 9,030,724 Flexible and Printable Electrooptic Devices. Forsimplicity, only the key aspects pertaining to the configuration andfunction of such pixels within a polymorphic display are describedherein and presented in 700 in FIG. 5A. Exemplary embodiment 700consists of an electro-optic layer 703 further including anelectropolymerizable monomer, an electrolyte (e.g. ionic liquid), and(optionally) highly reflective particles (e.g. TiO₂) collectively, hereand throughout, referred to as an “EC mix” (“electrochromic mixture”).The EC mix as illustrated is of a substantially uniform composition. Theelectro-optic layer 703, in this example, the EC mixture, is sandwichedbetween a pair of electrodes; a front electrode 704 and a back electrode705. The front electrode is at least partially transparent (e.g. ITO)and configured on a substantially transparent substrate 706 (e.g.,glass, plastic, etc.) and is advantageously sealed with abarrier/protective layer. The back electrode 705 and backsubstrate/barrier 709 may both either be transparent (for front and backside viewing of the display) or opaque (front side only viewing).

An advantageous mono-stable pixel 702 is now described that iscomplementary to the exemplary bi-stable pixel 701. Mono-stable pixel702 uses a conjugated (conductive) polymer film 710 that can switchreversibly between two distinctly different operable states when thepolymer is in contact with an electrolyte (such as the one contained inthe EC mix 703). The operable states correspond to a conductive(oxidized chemical) state and an insulating (neutral or reducedchemical) state according to the presence of a switching signal followedby a maintenance signal, or the termination or disruption of themaintenance signal. In the presence of an electrical switching signal,the pixel 702 transitions from a stable, first state to a volatilesecond state. The pixel remains in the volatile second state for theduration of the maintenance signal. When the maintenance signal isterminated (or disrupted for any reason) the pixel self-switches(transitions back) to the stable, first state.

Note that the EC mix 703 of pixel 701 comprises an electrolyte that canfunction as the electrolyte for pixel 702. The monomer and othermaterials in the EC mix do not prevent the electrolyte from use in bothpixels. Furthermore, as illustrated in FIG. 5A, the two pixels can havein common electrode 705, top and bottom substrates 706, 709, andbarrier/protective layer 707. Additionally, they can share a common,patterned electrode layer (and manufacturing process) comprising thepixel's respective front electrodes 704 and 711. They can also sharemask layer 708 described below. Not shown is the structure that wouldencapsulate the entire apparatus (e.g. the side barrier/protectivestructure) and the appropriate display driver circuitry with connectionsto the pixel electrodes.

In summary, polymorphic display 700 is a unitary apparatus comprisingtwo pixels, each a different type according to their respective operableproperties (bi-stable, permanent and irreversible, and mono-stable), andfurther that have in common, structure, materials and circuitry.

As noted above, the two pixels 701 and 702 share a single, commonelectrolyte layer. Furthermore, the switching voltages for the polymerfilms in the mono-stable pixel 702 are typically significantly lower(near 1V) than that typically required for electropolymerization (near3V) in the bi-stable pixel 701. This provides an upper threshold meansto keep the monomer in the EC mix from electropolymerizing yet allowingthe self-switching polymer 710 to switch between operating states byapplying a switching signal followed by applying and then terminatingmaintenance signal across the common back electrode layer 705 and thefront electrode 711. Although, the front electrodes, 704 and 711, forthe two operable pixel types of the polymorphic display 700 can be madeof different (transparent conductor) materials, it is preferably made ofthe same material by patterning a single front electrode layer depositedonto the single substrate 706. Depending on the locations of the addresslines/circuitry to the pixel electrodes of the display (not shown inFIG. 5A), while providing a high display contrast (dark background ofthe pixel openings), it may be advantageous to mask certain areas by anopaque, light absorbing material 708.

Of particular interest are self-switching mono-stable electrochromicpolymers having one stable and one volatile operating state, and twocorresponding optical states. These self-switching polymers may bedivided into two groups according to their chemical propertiescorresponding to their operable properties.

One group of electrochromic polymers are switchable from a stable,un-powered operating state corresponding to an oxidized chemical state,and a corresponding clear optical state, to a volatile, self-switchingoperating state corresponding to a neutral chemical state, and acorresponding colored optical state, and self-switching back to thestable, un-powered operating state and corresponding oxidized chemicalstate, and corresponding clear optical state. Exemplary polymers of thistype include dioxythiophenes (e.g. certain XDOT, such as PProDOT,PEDOT).

Another group of electrochromic polymers are switchable from a stable,un-powered operating state corresponding to a neutral chemical state,and a corresponding first, colored optical state, to a volatile,self-switching operating state corresponding to an oxidized chemicalstate, and corresponding second, colored or predominately clear opticalstate, and self-switching back to the stable, un-powered operating stateand corresponding neutral chemical state, and corresponding first,colored optical state. Exemplary polymers of this type include thiophenebased polymers (e.g. poly(methylthiophene)).

It should be noted that it is possible to achieve various colorcombinations by blending of two or more of such polymers within the samegroup and further switching them according to their specific thresholdvoltages. Additionally, and apart from electrochromic polymers, certainother materials including those based on transition metal oxides orderivatives of bipyridinium, such as, viologen, are self-switching. Forinstance, viologen can be adsorbed by a porous material, such asnanoparticle-based TiO₂, to form an active layer (e.g. in place of thepolymer layer 710), or added to the EC mix 703, and may additionallyfunction or co-function as the electrolyte.

It may further be advantageous to include an optional layer (also knownas a charge storage layer) consisting of a complementary conductingpolymer material 714 on the counter (back) electrode 705, to facilitatethe self-switching process and/or to add additional material layers toprotect the counter (back) electrode 705 from the electrolyte 703.Examples of such polymers include anodically coloring polymers, such asXDOPs (dioxypyrroles) or alternating copolymers of XDOT and carbazolessuch as PEDOT-NMe(Cbz), and cathodically coloring polymer such as XDOTssuch as PEDOT or PProDOT, which self-switch to an oxidized state.Cathodic materials may also be deposited to protect a bare counterelectrode including derivatives of bipyridinium, such as viologen, andanthraquinone and its derivatives in solution. An opaque or reflective(e.g. TiO₂ additive) EC mix may mask the electrochromic characteristicsof the above materials, or they may be intentionally included in theresulting optical states as seen from the front side or back side (for atwo-sided display).

Self-switching polymer films are typically prepared by spray casting 5mg/mL polymer solutions in toluene. When cured, the deposited layer maybecome a film less than sub-micron thick. Self-switching polymers may bedeposited onto the electrode using a variety of methods including:spray, spin, or drop casting neutral electrochromic polymer solutions;printing technology such as inkjet printing; dip casting from solution;and oxidative chemical vapor deposition of conducting polymer films orelectrochemical deposition. The properties of self-switching polymerfilms may further be manipulated through a chemical defunctionalizationstep rendering the film less soluble, allowing for deposition ofadditional layers such as the layer of EC mix 703.

Referring again to FIG. 5A, an individual pixel of the polymorphicdisplay 700 is switched by an electrical signal applied to itscorresponding electrode pair (704 and 705 or 711 and 705). Initially,both the states of the bi-stable pixel 701 and the mono-stable pixel 702are stable and each having a first, white optical state, 712 and 713, asdetermined by the reflective TiO₂ of the EC mix and the transmissiveproperty of the electrochromic polymer layer 710. Further, initially thecorresponding voltages across each respective electrode pair is 0V (715and 716).

FIG. 5B illustrates the respective optical states 718, 720 of thepolymorphic display 700 after application of respective independentswitching signals. The switching signal for irreversibly transitioningthe bi-stable pixel 701 into an irreversible and permanent operatingstate (e.g. dark blue optical state) can be accomplished through avariety of switching protocols such as those disclosed in U.S. Pat. No.9,030,724 Flexible and Printable Electrooptic Devices and U.S.provisional patent application Ser. No. 14/797,141 Device and Method toFix a Message on a Display, including e.g. applying a voltage above acertain threshold (as indicated by 719 of e.g. 3V) for a defined timeduration (e.g., 2 s). Note that the anode typically is the (front)electrode 704 such that the polymerized monomer 717 is (anodically)formed on or at the electrode, displacing the (white) EC mix and furtherproviding a substantial change of color (e.g. from white to dark blue)as observed from the viewing side. After the switching is complete, theoperable (and optical) state will remain as it is permanent andirreversible.

The switching signal for reversibly transitioning the mono-stable pixel702 into a volatile operating state (corresponding, e.g., to a red colorof the polymer layer 721 resulting in a red optical state 720 of thepixel) can be accomplished by, for example, applying a voltage above acertain threshold (as indicated by 721 of e.g. 1V) for a defined timeduration (e.g., 1 s). Note that the cathode is the front electrode 711in case of electrochromic polymers providing chemically neutral(reduced) volatile states (as shown in FIG. 5B) and oxidized stablestates (as shown in FIG. 5A) whereas the anode is the (front) electrodein case of electrochromic polymers providing chemically oxidizedvolatile states and neutral stable states. After the switching iscomplete, a maintenance signal is applied with the same effectivepolarity as the switching signal, in order for pixel to maintain itscurrent state. Upon termination or disruption of the maintenance signalthe volatile state will self-switch back to its original white state(713 in FIG. 5A). It should be noted, that depending on the depositionmethod employed of the electrochromic polymer layer in manufacture ofthe polymorphic display, some cycling (“break-in”) between thereversible states of the self-switching polymer may be advantageous toachieve faster switching times and/or higher color saturation. This isin particular applicable to deposition processes not providing forintercalated electrolyte within the polymer layer.

Example 2 (Polymorphic Pixel)

In this exemplary embodiment polymorphic functionality is achieved in asingle pixel, called a polymorphic pixel. Note that multiple (two ormore) polymorphic pixels with the same operable properties can also forma polymorphic display, as discussed above.

FIG. 6A illustrates an exemplary embodiment 800 of a polymorphic pixel801, in side view and front view. The pixel 801 follows the samevertical structure configuration as that of pixel 702 shown in FIG. 5A,and will thus not be described in detail except wherein there aredifferences that pertain to the polymorphic functionality. To this end,and for simplicity, the (optional) complementary conducting polymermaterial 714 is not shown and the EC mix 703, which together with theconducting polymer layer 710 form the electro-optic layer, initiallywill be assumed to contain highly reflective particles (e.g. TiO₂) as anadditive to the otherwise natively transmissive (clear) EC mix. Further,the polymer layer 710 is assumed be self-switchable, comprising aninitial stable, clear optical state and a corresponding oxidizedchemical state, switchable to a volatile red optical state with acorresponding reduced chemical state. A polymer which suchcharacteristics includes, e.g.,poly{3,4-di(2-ethylhexyloxy)thiophene-co-3,4-di(methoxy)thiophene}.

The functionality of the polymorphic pixel 801 will now be describedwith reference to the corresponding structure FIGS. 6A-E, and FIG. 7illustrating the operable states 900 through its applicable switchingsequences along branches 902 and 903.

Analogously to pixel 702, the initial (i.e., before any application ofan electrical signal to its front 711 and back 705 electrodes) operablestate 905 of pixel 801 is stable with a corresponding white opticalstate 804 (FIG. 6A), as determined by reflected light from the TiO₂particles of the EC mix 703 transmitted through the clear polymer layer710. After providing a switching signal (along branch 902) as indicatedby 806 in FIG. 6B, the operable state of the pixel switches to avolatile state 906 with a corresponding red optical state 807. Aspreviously discussed, this optical state will remain for the duration ofthe maintenance signal, after which it will self-switch back to itsoperable state 905.

The pixel 801 will remain in a self-switchable state along branch 902 aslong as the switching signal level does not exceed the threshold (e.g.3V) for electrochemical polymerization of the monomer in the EC mix 703.If, however, the applied voltage reaches the threshold voltage, with thefront electrode 711 being the anode, the monomer polymerizes 802 (FIG.6C) onto (or near) the self-switchable polymer layer 710. Note thatduring the switching the polymer layer 710 is in an oxidized chemicalstate, clear optical state, and electrically conductive state, whichfacilitates the polymerization process. After applying a switchingsignal (along branch 903) as indicated by 808, the operable state of thepixel switches irreversibly to a stable state 908 with a corresponding,e.g., dark blue optical state 809. This optical state is determined bythe color of the polymerized layer 802. Note that after the switching iscomplete, the self-switchable polymer layer will remain in a clearstate.

It is important to further note that even though operable state 908sequenced irreversibly from state 905, the pixel is now in a mono-stableand self-switchable operable state, as further applying a switchingsignal 811 (FIG. 6D) with a continued maintenance signal results in avolatile state 910 with red color of the self-switchable polymer layer721. Accordingly, the resulting optical state 812 will generally be acombination of 721 (here, red) and 802 (here, dark blue). For instance,and in this particular case, if layer 721 is relatively thick, theoptical state will be a predominantly red color; if layer 721 isrelatively thin (i.e. largely transmissive), the optical state willclosely match the dark blue color of layer 802; or, if 721 has athickness somewhere in the middle, the color may be a compound purple.Again, after removal of the maintenance signal, indicated by 813 in FIG.6E the pixel will self-switch back to operable state 908 (andcorresponding optical state 809).

In an alternative embodiment of pixel 800, the reflective TiO₂ particlesare not included in the EC mix 703 resulting in a transmissive (clear)optical property. This alters the optical state of the initial operablestate 904, depending on the reflective properties of the back electrode705. In this alternative embodiment the back electrode 705 is presumedlight absorbing (e.g. carbon black) resulting in an initial opticalstate of black as illustrated by 1001 of the operable states of thisembodiment 1000 in FIG. 8. However, the operable and optical states ofthe other states along branches 1002 and 1003 are the same as thoseillustrated and discussed in FIGS. 7, 902 and 903, respectively (hereassuming, for simplicity, that layers 721 and 802 are largelyreflective, and the yellow tint of the EC mix 703 does not contribute).

However, this particular embodiment enables additional operable statesby analogously polymerizing the monomer of the EC mix onto (or near) theback electrode by applying an opposite polarity of the switching signalonto the pair of electrodes. These additional operable states are shownalong an extended branch indicated by 1005, as well as, an additionalthird branch 1004, with operable states as indicated. Note that thevolatile optical states 1006 and 1008 are the same as 906, and that thestable optical states of 1010 and 1011 are virtually the same as 908(ignoring any effect of viewing through the transmissive EC mix).

In a further alternative embodiment of pixel 800, the reflective TiO₂particles are again not included in the EC mix 703, but an inert dye(here assumed yellow) is added resulting in a corresponding yellow tintof the EC mix. In this further alternative embodiment the back electrode705 is presumed light reflective. Advantageously, the concentration ofthe dye is such that light will be reflected through a double pass ofthe pixel stack yielding, in this case, an initial yellow optical state1001. Note that for this embodiment all other optical states remain thesame as above except for states 1010 and 1011, which will have a newoptical state of green, resulting from the dark blue polymerized layeron the back electrode viewed through the yellow tinted EC mix. Thus thisconfiguration can exhibit five different optical states, three stablestates and two volatile states, with a variety of operable propertiesincluding irreversible and mono-stable states.

Example 3 (Polymorphic Pixel with Non-Switchable Operable State)

FIG. 9A illustrates another exemplary embodiment 1100 of a polymorphicpixel 1101 with a non-switchable operating state, in side view and frontview. The pixel 1101 follows the same vertical structure configurationas that of pixel 801 shown in FIG. 6A, and will thus not be described indetail except wherein there are differences that pertain to thepolymorphic functionality. To this end, the reflective TiO₂ particlesare not included in the EC mix 703 resulting in a transmissive (clear)optical property. Further, the polymer layer 1102 is again assumed beself-switchable, comprising an initial stable, clear optical state and acorresponding oxidized chemical state, switchable to a volatile redoptical state with a corresponding reduced chemical state. However, theself-switching polymer layer 1102 is present on the back electrode 705(as opposed to the front electrode 711 as in FIG. 6A). Additionally, theback electrode 705 is reflective or transparent with an additionaldiffuse reflective layer behind it (not shown in FIG. 9A).

The functionality of the polymorphic pixel 1101 will now be describedwith reference to the corresponding structure FIGS. 9A-C, and FIG. 4illustrating the operable states 600 through its applicable switchingsequences along branches 601 and 602.

Analogously to pixel 801, the initial (i.e., before any application ofan electrical signal to its front 711 and back 705 electrodes) operablestate 610 of pixel 1101 is stable with a corresponding white opticalstate 1103, as determined by reflected light from back electrode 705.After providing a switching signal (along branch 601) as indicated by1104 in FIG. 9B, the operable state of the pixel switches to a volatilestate 620 with a corresponding red optical state 1106. As previouslydiscussed, this optical state will remain for the duration of themaintenance signal, after which it will self-switch back to its initialoperable state 610.

The pixel 1101 will remain in a self-switchable state along branch 601as long as the switching signal level does not exceed the threshold(e.g. 3V) for electrochemical polymerization of the monomer in the ECmix 703. If, however, the applied voltage reaches the threshold voltage,with the back electrode 705 being the anode, the monomer polymerizes1108 (FIG. 9C) onto (or near) the self-switchable polymer layer 1102.Note, again, that during the switching the polymer layer 1102 is in anoxidized chemical state, clear optical state, and electricallyconductive state, which facilitates the polymerization process. Afterapplying a switching signal (along branch 602) as indicated by 1107, theoperable state of the pixel switches irreversibly to a stable state 630with a corresponding, e.g., dark blue optical state 1109. This opticalstate 630 is determined by the color of the polymerized layer 1102 asthe EC mix 703 is transmissive. Note, again, that after the switching iscomplete, the self-switchable polymer layer will remain in a clearstate. However, in contrast to Example 1 above, this operable state doesnot allow for any further switching affecting the corresponding opticalstate 1109, thus it is in an operable state which is non-switchable.

Example 4 (Interdigitated Electrode Structure)

In the exemplary embodiments discussed above, the electrode layers forswitching the electro-optic layers have been focused on non-patternedconfigurations with either transparent or opaque optical properties.However, in some cases it may be advantageous to use an interdigitatedpair of electrodes. Such configurations enable a single patternedelectrode layer instead of two separate non-patterned electrode layerssimplifying the manufacturing process of polymorphic pixels anddisplays. Furthermore, this allows for two activation surfaces perinterdigitated electrode pair in a single layer with a multitude ofoperable states. Note that such an interdigitated transparent electrodestructure (e.g. ITO) can also be employed on both sides of theelectro-optic layer, e.g., for a two-sided display.

FIG. 10A shows (in a back side view) a conceptual electrode layout 1200consisting of four pairs of interdigitated electrodes (corresponding tofour pixels of the completed polymorphic display). In this configurationone digitated electrode of each of the four pairs is (optionally)connected to a common electrode connection 1220. Thus any particularpair of electrodes can be addressed using the common electrode 1220 anda pixel specific digitated electrode (e.g. 1210).

Typically the interdigitated electrode layer is deposited (e.g. directlyprinted or by patterning of a uniform film using, e.g. photolithographyor laser ablation) onto a substrate 1230 (outlined). This process isfurther followed by deposition (e.g. printing) of one or moreself-switching polymers (all in the same layer), such as shown in 1300by a first self-switching polymer 1310 and a second self-switchingpolymer 1320. Note that the deposition can continuously span of morethan one electrode pair (such as in the case of 1310).

Advantageously, the widths and separation of the electrode digits areoptimized with respect to the particular properties of theself-switching polymer (e.g. thickness) and switching protocol. However,also depending on these properties, it may be preferable (e.g. forbetter color contrast) to only deposit (e.g. print) the self-switchablepolymer along the electrode digits (i.e. with gaps), and further only onone side of the interdigitated pair (a complementary polymer layer mayoptionally be deposited on the other side of the interdigitated pair).

After completion of the self-switching polymer layer, the EC mix layercan be deposited (e.g. by a further printing process), as shown by layer1410 in FIG. 10B. In this particular case, the EC mix is opaque (white,containing TiO₂ particles), however, it may also be transparent (withoutTiO₂ particles) as shown in 1500 by layer 1510. Note that the EC mix canalso be deposited onto select pixels using different EC mix compositions(e.g. a different monomer polymerizing to a unique color). Furthermore,depending on the operable states desired for the polymorphic display,some pixels may only have an electrolyte printed on top (i.e. no ECmix).

The above examples disclose embodiments of polymorphic displays andpixels with various operable states corresponding to optical statesdetermined by reflective properties of the pixels. However, the methodand means can advantageously be extended to transmissive and/orpolarization properties. For example, the self-switching polymer orpolymerized monomer layers can be designed (with appropriate activationprotocols) such that the transmitted light through (the colored layersin) the pixels determine the optical state. In this case, both the backelectrode and substrate are at least partially transmissive as well.Advantageously, electrochromic materials could be combined with a liquidcrystal material to from an electro-optic layer capable of generatingboth polarization and color changes to transmitted light through thelayer (with corresponding operable states). Optionally, polarizers infront and behind the electro-optic layer (e.g. on the outer surface offront (and back, if transmissive) substrate or cover layer, could, e.g.,convert the polarization changes to light intensity changes.

Additionally, the above exemplary embodiments primarily working in thevisible wavelength range. However, as discussed above, the embodimentsof the current invention also include wavelength outside of the humanvisible range (e.g. machine reading). Advantageously, as electrochromicpolymers typically exhibit significant reflectivity changes in the IRwavelengths between the oxidized (conductive) and reduced(non-conductive) states, these materials can thus also be utilized forgenerating operable state changes outside of the visible range forpolymorphic pixels and displays.

Example 5 (Polymorphic Display—Fixed-Image Shutter Mode)

FIG. 12A-D illustrates another embodiment of the current invention inside view and front view, in which the pixels of a polymorphic display1600 operates in a shutter mode (i.e., a means for either transmittingor reflecting/absorbing light). This embodiment is similar to thatillustrated in FIG. 5A, thus only differences will be highlighted. TheEC Mix 703 spanning both the right pixel 1601, with a bi-stable,permanent and irreversible second operating state, and the left pixel1602, which is monostable and self-switchable, is predominantlytransparent (i.e., without any TiO2 in the EC Mix). Although the(optional) complementary conducting polymer material 714 of FIG. 5A isnot shown, it should be noted that the complementary conducting polymermaterial 714 can be patterned appropriately to all or a set of pixels ofthe polymorphic display. Additionally, the material may be pixelspecific according to the intended properties of the correspondingpixel. As presented in FIG. 5A, embodiment 1600 additionally comprises afixed-image layer 1603 containing fixed-images 1604 (here a “smileyface”) and 1605 (here a “check mark”), which both can be revealed orobscured to the viewing side depending on the transmissive properties ofthe respective pixels 1601 and 1602. Note that here the polymorphicdisplay is illustrated functionally as an indicator with two pixelslarge enough to each contain a legible image. It should be understoodthat the image layer may contain one or more images (also referred toherein as messages) and a polymorphic display may comprise multiplefixed-image layers. Further note that fixed-image layer 1603 may includeonly discrete images (such as 1604 and 1605) with no (printing) layermaterial in-between, as shown in FIGS. 12A-D.

The fixed-images, 1604 and 1605, may e.g. be printed or otherwiseconstructed or placed directly onto substrate 709 or onto a separatethin substrate or film (not shown) which subsequently is adhered tosubstrate 709. The back electrode 705 of this embodiment shown in FIG.12A is transparent such that a fixed-image located on the back-side ofthe back electrode may be seen from the viewing side. However, it willbe appreciated that the fixed-image may also be printed or placeddirectly onto the front side (not shown) of an optionally opaque backelectrode 705, for instance, with the fixed-images printed usingconductive ink of a favorably different color than the opaque electrodeto provide image contrast. In either case the fixed-images may also beprinted in full color. Additionally, the fixed image may also be printedor placed directly on the front side of the optional complementaryconductive polymer material 714 shown in FIG. 5A), advantageously withan image construction and material which provide for sufficient imagecontrast and ion conductivity (e.g., porous, containing small holes).Note that “fixed images”, as the term as used herein, may also include“dynamic” images that are generated after manufacture of the polymorphicdisplay (at a preferable point during the switching cycle). Forinstance, with a patterned back electrode 705 (e.g., interdigitated pairper Example 4 or segmented) a desired image could be generated bypolymerization of EC mix 703 onto the corresponding electrode pattern(by respective application of an activation signal across theinterdigitated pair of electrodes or back segmented and frontelectrodes).

In the particular embodiment 1600 illustrated in FIG. 12A-D, theself-switching polymer 1606 is different than those previously discussedin Example 1, in that its stable (non-powered) state is colored (e.g.black or blue), whereas its volatile state is transparent or clear(here, for example, in the human visible wavelength range). Exemplarypolymers with such characteristic include anodically coloring conductivepolymers with low oxidation potentials, such as, PBEDOT-NMeCbz andPProDOP-NPrS.

FIG. 12A illustrates the initial state of the polymorphic display 1600prior to any application of switching signals across electrodes 704 and705 of pixel 1601 and 711 and 705 of pixel 1602. In this stablepre-switched state, the vertical structure of pixel 1601 is transparentallowing fixed-image 1604 (“smiley face”) to be seen 1607 from theviewing side (indicated by 1607 in the front view of FIG. 5A). Theself-switchable polymer of pixel 1602 however is colored (and favorablyalso opaque) in its unpowered stable state, thus the fixed-image 1605 ofpixel 1602 is obscured or hidden from the viewing side (indicated by1608 in the front view of FIG. 5A). After subsequent application of aswitching signal to pixel 1602 (e.g. −1V onto front electrode 711relative to common electrode 705) a resulting transparent state of theself-switching polymer layer 1607 reveals fixed-image 1605 (“checkmark”), as shown by 1610 in FIG. 12B. The fixed-mage 1605 will remainvisible for the duration of the maintenance signal (e.g. indicating thatdevice is operating). Analogous to pixel 701 in Example 1 and asillustrated in FIG. 12C, pixel 1601 is switched by applying a voltageabove a certain threshold (e.g. +3V), such that the polymerized monomerlayer 1611 is formed at the front electrode 704 of pixel 1601. Thisswitching signal can for instance be in response to an event, e.g., thetemperature of the display itself or the good the polymorphic display isattached to, exceeded a set threshold. As the polymerized monomer layer1611 is colored (e.g. dark blue), and advantageously opaque, fixed-image1604 is now hidden in a permanently and irreversibly hidden or obscured,as indicated by 1612 in FIG. 12C. Subsequently, and as illustrated inFIG. 12D, upon termination of the applied maintenance signal to theelectrodes of pixel 1602 (e.g., in this case indicating a powerfailure), the self-switchable polymer reverts back to its stable coloredstate 1606, resulting in both fixed-images being hidden, as indicated by1608 and 1612 in FIG. 12D.

As discussed above, there are many electrochromic conductive polymerswhich are mono-stable and self-switchable and could be used as layerwith either a transparent (clear) state in the stable state (e.g., 710in FIG. 5A) or self-erasing state (as indicated by 1609 in FIG. 12B).However, there are also some that are bi-stable with bothself-switchable and irreversibly switchable operable properties. Suchpolymers provide for expanded shutter mode functionality. Specifically,the operable states of such a pixel 1700 as shown in FIG. 13, exhibit afirst colored stable state 1740 as deposited (e.g. spray casted), andare irreversibly switchable to a second colored or transmissive stablestate 1760 after applying a first switching signal, and furtherswitchable to a third colored volatile state 1780 after applying asecond switching signal. Analogous to above, it will remain in thevolatile third state 1780 for the duration of the maintenance signal.When the maintenance signal is terminated (or disrupted for any reason)it self-switches (transitions back) to the stable, second state 1760.

For example, the first stable state for a spray cast film of adisubstituted poly(propylenedioxythiophene) PProDOT(CH₂OEtHx)₂[Macromolecules, 2004, 37 (20), pp 7559-7569] (prior to power beingapplied for the first time) is red 1740, the second stable statecorresponding to an oxidized chemical state (after a first switchingsignal is applied) is transparent (or clear) 1760, and the thirdvolatile state corresponding to a neutral (reduced) chemical state(after a second switching signal followed by a maintenance signal isapplied) is blue 1780. The third state is achievable through aphenomenon called “doping induced order” where the expulsion of theelectrolyte allows a reorganization of the polymer backbone to a lowerenergy state. Such an exemplary three-state polymer could advantageouslybe applied as layer 1606 of pixel 1602 of the polymorphic displayshutter structure 1600 in FIG. 12A. For example, with such a three-statepolymer, pixel 1602 could provide augmented indication (or message),that the display (and associated good) has never been powered up oractivated by indication of a stable red state, which is irreversiblyswitchable to a second clear and stable state (revealing image 1605),followed immediately by a second switching signal transitioning to thethird volatile blue state (indicating the power is on). If themaintenance signal in this state is subsequently terminated (forinstance, when power is no longer available), it self-switches back tothe second clear state revealing image 1605 (which, in this case, mayindicate a “no power” symbol).

Note that polymers with such characteristics can, for example, also beutilized as material layer 710 of pixel 702 in FIG. 5A or of pixel 801in FIG. 6A, to provide for bistable, irreversibly switchable, andself-switchable operable properties in conjunction with appropriatelyselected switching signals and signal protocol.

Example 6 (Compartmentalized Structure)

In some polymorphic display configurations it may be desirable tocontain the EC mix or electrolyte material by means of compartmentswithin a common structure as illustrated by polymorphic displayembodiment 1800 in FIG. 14. This is, in particular, applicable for casesin which the EC mix or electrolyte is characterized by a relatively highviscosity (e.g., after deposition or printing). However, it is alsoadvantageously utilized for polymorphic displays for which individualpixels require different types of electrolytes (for optimizedelectrochromic functionality) or comprise distinct electro-opticmaterials. Such electro-optic materials may comprise any material thatcan affect reflected, transmitted, or emitted electro-magnetic radiation(e.g., amplitude, intensity, polarization, and/or wavelength) based onan electric input (e.g. switching) signal. Examples of suchelectro-optic materials include liquid crystals (e.g., cholesteric andferroelectric), electrophoretic (particle systems), electrochromicmaterials, electrowetting fluids, electro-liquid powder materials,plasmonic nanostructures, optical interference stacks (including thoseswitched by microelectromechanical systems), photonic crystals, andphosphorescent materials, as well as, emissive materials such as LEDmaterials, OLED (and other electroluminescent) materials, quantum dotmaterials (photo-emissive or electro-emissive), or any combinationthereof. Note that such compartmentalized structures may also beutilized for hybrid displays for which the achievable operable states ofeach pixel are the same but, for instance, the achievable optical statesare different.

Embodiment 1800 is similar to embodiment 1600 in FIG. 12A without thefixed-image layer 1603, and will not be explained in detail expect wherethere are differences. The key difference of embodiment 1800 as comparedto embodiment 1600 is the integration of a compartmentalized structure(vertically) spanning the front transparent substrate 706 and the back(here common) electrode 705, thus providing containment of the EC mix703 of pixel 1801 and electrolyte 1803 (e.g. ionic liquid) of pixel1802. The thickness of the containment wall 1806 in-between pixels (here1801 and 1802) may be different (e.g. thinner as shown) as compared tothose containing edge pixels of the polymorphic display (here 1804 and1805). The thicknesses and aspect ratios of the walls are favorablyoptimized taking into account the compartmentalized structure material(e.g., flexible polymer), rigidity (or viscosity) of the EC mic 703 andelectrolyte 1803, flexibility of the display, as well as, functionalityand lateral fill factor of the pixels. For high resolution displays, itmay further be preferable that the compartmentalized structure materialbe made opaque (e.g. by adding a light absorbing dye or ink particles)to enhance the image quality of the completed polymorphic display.

The compartmentalized structure may, for instance, be fabricated from asolid uniform film by accordingly removing material (e.g. by laserablation), before it is applied (with e.g. an adhesive) to the frontsubstrate 706 or back substrate 709 (with transparent of opaqueconductive layer 705), or generated in place by a photolithographicprocess.

In an alternative variation of embodiment 1800 (commonly used forpixelated electrophoretic displays), the compartmentalized structure maybe generated through an embossing process, e.g., by embossing athermoplastic or photopolymer layer onto conductor layer 705 supportedby back substrate 709, with subsequent filling/sealing of theelectro-optic material, and attachment to the front substrate 706 (withpixelated transparent conductors). Such a structure would enableswitching of polymorphic display pixels based on, for example,electro-optic materials that respond to an electric field including,e.g., electrophoretic and liquid crystal materials. However, in thisalternate embodiment without direct exposure to back electrode 705 (e.g.through removal of any residual embossing material), electro-opticmaterials requiring low resistive interface to its correspondingelectrodes (such as electrochromics) would not switch. Advantageously,however, such electrochromic functionality can be achieved bysubstituting the front pixel electrode (e.g. 704 or 711) with a pair ofinterdigitated electrodes (as illustrated in Example 4).

Example 7 (Alternate Compartmentalized Structure)

In some polymorphic and hybrid displays it may advantageous to provide acommon compartmentalized structure for only some of the pixels in thedisplay. For instance, electro-optical material compositions that arerelatively solid or semi-solid after deposition (and potentially curingor solidifying) may not require a permanent support structure. Suchelectro-optic materials include those favorably formed into films, withor without a permanent (or temporary) supporting substrate, in separateprocesses for subsequent integration into the polymorphic or hybriddisplay. FIG. 15A illustrates an embodiment 1900 of such a polymorphicdisplay in its pre-powered state, in side and front views, with two(indicator) pixels comprising a bi-stable electrophoretic right pixel1901 and a monostable and self-switchable left pixel 1902.

The left pixel is functionally similar to pixel 702 illustrated in FIG.5A, thus only differences will be highlighted. For simplicity, theoptional complementary conductive polymer material 714 is not shown. Theelectrolyte 1803 (e.g., ionic liquid) may be transparent or contain acoloring additive (e.g., TiO₂). Structurally, pixel 1902 is similar tothat of 1802 of embodiment 1800, discussed in Example 6, withcontainment walls 1804 and 1806. In the stable pre-powered colored (hereshown as black) state of the conductive polymer layer 1606, theindicator output 1912 of pixel 1902 is black, as shown in FIG. 15A.

The right pixel 1901 comprises an electrophoretic microencapsulatedelectro-optic layer of spheres 1920 filled with suspension fluidcontaining two types of oppositely charged ink particles, white 1921 andblack 1922. These particles move in response to an applied electricfield between electrodes 704 and 705, such that white ink particles 1921remain stable at the front surface after application of a switchingsignal applied to the electrodes (of a specific polarity), whereas theblack ink particles 1922 (of opposite charge) remain stable at the backof the electro-optic layer as shown in FIG. 15A. Thus as shown in FIG.15A, the resulting indicator output 1911 of pixel 1901 is white.

With the pre-powered state of embodiment 1900 in FIG. 15A discussedabove and referring to FIGS. 15B-E an exemplary switching sequence ofembodiment 1900 is now detailed. In FIG. 15B pixel 1902 is switched(analogously to pixel 1602 in FIG. 12B) to its volatile state (e.g.indicating the display is powered up), resulting in a clear state ofpolymer layer 1609 and a white state of the indicator output 1914 (hereassuming, for example, that electrolyte includes a TiO₂ coloringadditive). The state of indicator will self-switch back to output 1912,as shown in FIG. 15C, if the corresponding maintenance signal is nolonger applied to the electrodes of pixel 1902, e.g., if a loss of poweroccurs. If, however, the maintenance signal remains with the display(indicator) in a powered state, pixel 1901 can favorably indicate theoccurrence of an event (e.g., the temperature of the display orassociated good exceeds a set limit) by switching the state of theelectrophoretic electro-optical layer such that the black ink particlesare now instead at the viewing side, corresponding to a black stablestate of the indicator output 1915 as shown in FIG. 15D. Finally, if asubsequent loss of power occurs, pixel 1902 reverts back to blackindicator output state 1912 with the bi-stable indicator outputremaining black, as indicated by 1915 in FIG. 15E. Note that in thisparticular embodiment 1900 both pixels are reversible. Thus after areset of pixel 1901 (to a white state initial state) the entire sequencecan be repeated.

Commonly, electrophoretic microencapsulated electro-optic layers areformed in roll-to-roll processes onto a non-patterned electrode layer ona support substrate. This allows for prefabrication of theelectrophoretic electro-optic layer of pixel 1901 of embodiment 1900onto back substrate 709 with the non-pattered electrode layer 705 usingan adhesive 1915. The area of the prefabricated substrate 709 withexposed electrode 705, commonly used for required electrical connection(e.g. using conductive adhesive), can also be used, and extended ifnecessary, as a means to form the compartmentalized structure (1804 and1806) onto. Advantageously, the compartmentalized structure may also beformed onto front substrate 706 facilitating alignment to pixelatedelectrodes (704 and 711). In either case the electrophoreticelectro-optic layer is attached electrode 704 and substrate 706 by atransparent adhesive 1925, whereas the pre-filled electrolyte material1803 is sealed by the adhesively attached compartmentalized structure.Note that depending on the particular configuration including theseparation (“dead space”) between pixels 1901 and 1902 and substratethicknesses of 706 and 709, the thickness of the compartmentalizedstructures 1806 and 1804 (defining the thickness of electrolyte material1803) may be different than that of the electrophoretic electro-opticlayer of pixel 1901, and the structure wall 1806 may be optional.

It will be appreciated that there are many variations of exemplaryembodiment 1900 of FIG. 15A. For example, it may be advantageous toconfigure in an “inverted” structure such that the prefabricatedelectrophoretic electro-optic layer with non-patterned electrode layerfaces the viewing side. Although this would require the non-patternedelectrode layer to be transparent, it would allow the back patternedelectrode layer, as well as, the (optionally conductive) adhesive 1925to be opaque. Further, the self-switching conducting polymer layer couldbe either printed on the front prefabricated electrode layer or on theback patterned electrode layer. The latter case would preferably includea transparent electrode material 1803, as the polymer layer is viewedthrough the electrolyte.

Additionally, it should be noted that although exemplary embodiment 1900in FIG. 15A illustrates an electrophoretic display pixel 1901 with twodistinct states, electrophoretic electro-optic materials may alsocomprise a multitude of stable states (e.g., a number of stabledistinguishable grey levels); or contain three or more types of inkparticles and/or a colored suspension fluid with corresponding stablecolor states.

Example 8 (Pixels Constructed with Different Redox and ElectrolyteLayers)

As discussed above, there are many advantages to achieve irreversiblemodalities in polymorphic pixels and displays using single layers of ECmixtures (comprising monomers and electrolytes). In some cases, however,it may be desirable to achieve different operable properties by creatingpixels that comprise separate redox layers (layers comprised of redoxmaterials such as electro-polymerizable monomer(s) or conductivepolymers and electrolyte layers). And further, where the redox layers(or the electrolyte layers) are advantageously solid or semi-solid,porous or a gel; flexible, semi-flexible or rigid.

As with electro-polymerizable monomers disbursed within an EC mixture,electro-polymerizable monomer layers are polymerized in-situ, i.e.within the display device. One preferred embodiment is a polymorphicdisplay comprising different sets of pixels, each comprising differentredox layers and a shared electrolytic layer that spans multiplepixels—and can provide independent pixel switching. Independentswitching is achieved for example with a polymorphic display comprisinga permanent and irreversible pixel (constructed with anelectropolymerizable monomer layer) and a self-switchable pixel(constructed with a conductive polymer layer), where the two pixelsshare a common electrolytic layer, even if the respective switchingvoltage levels are comparable and/or their ranges are overlapping (i.e.,not highly non-linear with distinct threshold voltages).

Favorable redox materials (e.g., electropolymerizable monomers andconductive polymers) for redox layers are those that are solid in thetemperature range of interest of the display device (e.g. operating andstorage temperature ranges), in contrast to those that form liquids (ofvarious viscosities) suitable for single-layer EC mixtures. Further, theelectro-polymerizable monomers (and subsequently polymerized monomers)are preferably insoluble in the electrolyte, which improvescompatibility with a large range of electrolytes (e.g. ionic liquids).For example, hydrophobic monomers would be less likely todissolve/disperse in polar ionic liquid.

Of particular interest are electro-polymerizable monomers (includingmacromonomers and oligomers) that are characterized by relatively highmolecular weight, e.g. benzophenone, benzothiadiazoles, carbazoles,fused aromatic ring systems, fluorenone, and further specificallyfluorinated monomers (and compounds), as they tend to aggregate togetherto form solid layers. Electro-polymerizable monomers that oxidize atrelatively high potentials (say, for example, at +0.1V vs. Fc/Fc+ orhigher) are also advantageous as these are less susceptible to oxidationand therefore more stable in (pre-switched) display devices and thusreducing or eliminating the need for high-performance device barrierlayers/encapsulation.

A electro-polymerizable monomer layer may be deposited onto theelectrode layer (e.g. 704 or 705 of of pixel 701 in FIG. 5A) using avariety of methods (similar to the conductive polymer layer forself-switchable pixel, see e.g. 710 of pixel 702 in FIG. 5A), includingspray casting, screen or inkjet printing, gravure coating, etc. Thesedeposition methods may further be solution based (solvent assisted)using either polar or non-polar solvent depending on the monomer'sproperties, and include other additives such as polystyrene (to increaseviscosity) or adhesion promotors (e.g. Silquest 187-A Silane; orEDOT-acid as a separate sub-layer). Exemplary solvents includecyclopentyl methyl ether (CPME), 2-methyltetrahydrofuran,dihydrolevoglucosenone (cyrene), acetonitrile, etc. Similarly to the ECpolymer layer for self-switchable pixels (e.g., 710 of pixel 702 in FIG.5A-B), electro-polymerizable monomer layers may be patterned onto(partially or substantially conforming to) a pixelated electrode, ordeposited as a continuous (shared) layer across multiple pixelelectrodes (favorably with sufficient spacing between neighbor pixelelectrodes). Deposited (and patterned) electro-polymerizable monomerlayers may have pixel-specific monomer properties to achieve pixelparticular optical states (e.g. colors) and/or pixel specific modalitiesfor polymorphic displays. The redox layer may also contain multipleelectropolymerizable monomers to achieve a broader spectrum of opticalstates, e.g. by blending the monomers in different ratios to form asingle solid layer, forming multiple solid sub-layers each with adifferent polymerizable monomer, or any combination thereof. Themultiple monomers may also comprise dissimilar (e.g. distinct oroverlapping but shifted ranges of) polymerization activation thresholdsto achieve different optical states by application of distinct switchingsignals/protocols (e.g. voltage levels, durations, etc.) to theaddressing electrodes.

The electrolyte layer may include solid polymer electrolytes, gelpolymer electrolytes, and polyelectrolytes, with green alternatives ingel polymer electrolytes based on e.g. cellulose or lignin, or ionicliquids. Advantageously, the electrolyte may also be deposited using avariety of printing techniques, as previously discussed, and may be aliquid (favorably contained) or (highly) viscous layer (with increasedmechanical and interfacial stability by additives including, e.g.zeolites, Al₂O₃, MgO, or SiO₂), or advantageously made semi-solid orsolid with appropriate additives (e.g. thermally or UV curable monomers,microbeads, etc.) to form fully solid device stacks (including theelectrode materials). The electrolyte layer may additionally includecolorants (e.g., pigments, dyes, or TiO₂).

Solid electro-polymerizable monomer layers can provide for a multitudeof operable properties for polymorphic display pixels and polymorphicpixels. In the case of a single substantially uniformelectro-polymerizable monomer layer, the polymodal properties andmodalities include a first stable state, corresponding to a firstoptical state (e.g. a first color) as deposited. The first state isirreversibly switchable to a second state (by oxidativelyelectropolymerizing the solid monomer layer), corresponding to a secondoptical state (e.g. a second color), which may be either stable orvolatile depending on the properties of the monomer. In case of a stablesecond state, the polymerized (oxidized) monomer may further beswitchable to a volatile third state (i.e., analogous to the operablestates 1700 shown in FIG. 13), corresponding to a third optical state(e.g. a third color), and remain in this (reduced polymerized) state forthe duration of the maintenance signal (as discussed above). When themaintenance signal is terminated (or disrupted for any reason) itself-switches (transitions back) to the stable, second state. Whereas inthe case of a volatile second state, the electropolymerized monomerremains in this state for the duration of the maintenance signal afterwhich it self-switches to a third stable state, corresponding to a thirdoptical state (e.g. a third color). Note that the respective opticalstates, i.e. first, second, and third colors of the solid EC layer(either the monomer or the electropolymerized monomer) may correspond toa transparent, lightly colored semi-transparent, or colored opaquestate, which may be non-reflective (absorptive), semi-reflective, orreflective. In the case of transparent or semi-transparent properties,or relatively thin layers, the pixel color may be different than themonomer layer depending on properties of the layer(s) viewable behindthe redox layer (e.g. through intentional color blending by means of acolored electrolyte and/or back electrode/substrate or reflectiveinterference stack effects). The third optical state may also beindistinguishable from that of the second state (e.g. for a wavelengthor within a wavelength range).

A single electro-polymerizable monomer layer (including sub-layers ofelectro-polymerizable monomers) may also be deposited on the back(counter) electrode of a pixel (e.g., instead of the self-switchingpolymer layer 1102 of polymorphic pixel 1101 in FIG. 9A), or layers ofthe same or different monomer properties on each electrode (with thecompleted display device viewable from one or both sides), to achievedifferent polymorphic modalities. Although an irreversible switchingmodality can be achieved with a separate electro-polymerizable monomerlayer in conjunction with an adjacent electrolyte layer, an EC mix layer(e.g., 703 of embodiment 1100 in FIG. 5A), which includes polymerizablemonomers, could also be used as the electrolyte layer to achieveadditional irreversible transitions, e.g. with the electro-polymerizablemonomer layer and the in-mix monomer layer activated at differentpolymerization thresholds.

FIG. 16A shows an exemplary configuration of a polymorphic display 2000comprising two pixels, each having different operable properties, inside view and front view. For illustration purposes, only two pixels areshown although it is to be understood that a polymorphic display maycomprise many such pixels (and sets of pixels). The right pixel 2001,comprising a solid monomer (redox) layer 2011, is bi-stable with bothself-switchable and irreversibly switchable operable properties (such as1700 in FIG. 13), whereas the left pixel 2002 is mono-stable andself-switchable (such as 100 in FIG. 1).

The left pixel 2002 of FIG. 16A is similar to pixel 702 in FIG. 5A, thusonly differences will be discussed. Specifically, instead of having anEC mix 703 functioning as an electrolyte, pixel 2002 (and pixel 2001)comprises a shared electrolyte (without a monomer) which is coloredyellow (e.g. ionic liquid with an appropriate pigment or dye). Theself-switchable redox layer comprising a conductive polymer 2010 isgreen in its volatile state and substantially transparent in its stablestate [e.g. a spray cast film of ECP-G Chem. Mater. 2012, 24, 255-268].FIG. 16A shows pixel 2002 prior to application of a switching signal (topixel electrode 711 and common electrode 705), with the pixel having atransparent conductive polymer layer 2010, and a corresponding yellowoptical state 2013. FIG. 16B shows pixel 2002 after application of aswitching signal (and application of a maintenance signal), resulting ina green polymer layer 2021, and a corresponding green optical state2020. The pixel remains in its volatile state until the maintenancesignal is terminated, at which point it self-switches back to its yellowstable state 2013 as shown in FIG. 16C.

The right pixel 2001 is similar to pixel 701 in FIG. 5A, thus onlydifferences will be discussed. Specifically, this exemplary embodimentcomprises a redox layer comprising a solid electro-polymerizable monomer2011 of fluorenone-thienylene vilylene [TVF](((2,7-bis(5-[(E)-1,2bis(3-octylthien-2-yl)ethylene])-fluoren-9-one)[“Solution versus solid-state electropolymerization of regioregularconjugated fluorenone-thienylene vinylene macromonomers—voltammetric andspectroelectrochemical investigations”, R. Demadrille et al., J SolidState Electrochem (2007) 11:1051-1058]. This exemplaryelectro-polymerizable monomer 2011 is red in its first stable state(prior to power being applied for the first time), with the pixel 2001having a corresponding red optical state 2012 as shown in FIG. 16A. Thisoperable state is irreversibly switchable, by applying a switchingsignal across pixel electrodes 704 and 705, to a second stable state,corresponding to a light blue in color (2018 in FIG. 16B). The change inthe operable state and optical state (color) occurs by solid-stateelectropolymerization of the solid TVF monomer in conjunction with theshared electrolyte layer 2003 of pixel 2001. The light blue polymerizedlayer 2018 is partially transparent (and reflective) and color blendswith the yellow electrolyte layer 2013 to yield an approximately greenoptical state 2019. It can be appreciated that the composite color ofthe optical state 2019 can be tuned, e.g. by selection of monomer layer2011 thickness, concentration and selection of electrolyte colorant, oractivation protocol (e.g. duration of activation signal). For example,it may be desirable to color match the composite optical state 2019 tothe optical state 2020 of the volatile state of self-switching pixel2002. Further, after application of a second switching signal thepolymerized layer switches to a volatile third state, which isorange/red 2014, with a corresponding orange/red optical state 2015 ofpixel 2001, as shown in FIG. 16C (note that the orange/red color andcorresponding pattern used in FIG. 16C is not included in the Legend ofFIG. 11). Analogous to above, the pixel 2001 will remain in thisvolatile state (and corresponding optical state 2019) for the durationof the applied maintenance signal. Upon termination of the maintenancesignal the pixel self-switches back to its stable, second optical state2019.

Other combinations of the polymorphic display 2000 are also possible.For instance, pixel 2002 could be constructed as pixel 2001 but with asolid monomer comprising a different modality of e.g. a volatile secondstate and a stable third state. Alternatively, it could be constructedas a display with pixel 2002 having the same modalities as (polymorphic)pixel 2001, however, with a second monomer having different opticalproperties in one or more states of those corresponding to pixel 2001.

It will be appreciated that although pixel 2001 comprises a solidelectropolymerizable monomer (redox) layer 2011 in combination with anelectrolyte layer 2003 which may be a liquid, semi-solid or solid, itcould alternatively, or additionally (e.g. two redox sublayers),comprise a liquid electropolymerizable monomer layer in combination witha semi-solid, gel, or solid electrolyte layer. Alternatively, the redoxlayer may contain a liquid monomer in a mix (e.g. an EC mix as above) orform a gel or semi-solid layer (e.g. by adding for example zeolites,Al₂O₃, MgO, or SiO₂, or polymer such as polystyrene to the mix, orproviding a porous or a printed microscale structure for the layer).

While particular preferred and alternative embodiments of the presentintention have been disclosed, it will be appreciated that many variousmodifications and extensions of the above described technology may beimplemented using the teaching of this invention. All such modificationsand extensions are intended to be included within the true spirit andscope of the appended claims.

What is claimed, is:
 1. A polymorphic display comprising; a plurality ofpixels; the plurality of pixels each comprising a redox layer and anelectrolyte layer, the electrolyte layer configured adjacent to theredox layer; a first set of pixels from the plurality of pixels, theredox layer of all the pixels in the first set of pixels comprising afirst redox material; a second set of pixels from the plurality ofpixels, the redox layer of all the pixels in the second set of pixelscomprising a second redox material, wherein the operable properties ofthe pixels of the first set and the operable properties of the pixels ofthe second set are determined by their respective redox layers.
 2. Thepolymorphic display according to claim 1, wherein the redox layer of thefirst set of pixels comprises a first electropolymerizable monomer, andthe redox layer of the second set of pixels comprises a secondelectropolymerizable monomer.
 3. The polymorphic display according toclaim 1, wherein the redox layer of the first set of pixels comprises anelectropolymerizable monomer, and the second redox layer comprises aconductive polymer.
 4. The polymorphic display according to claim 1,wherein at least one of the operable properties of the second set ofpixels is different as compared to the first set of pixels.
 5. Thepolymorphic display according to claim 1, wherein the electrolyte layerof the first set of pixels is the same electrolyte layer as that of thesecond set of pixels.
 6. The polymorphic display according to claim 1,wherein the electrolyte layer of the first pixel set is the same as theelectrolyte layer of the pixels of the second pixel set.
 7. Thepolymorphic display according to claim 1, wherein the electrolyte layerof the second set of pixels is different as compared to the electrolytelayer of the first set of pixels.
 8. The polymorphic display accordingto claim 1, wherein the redox layer of at least one of the plurality ofpixels is pixelated.
 9. The polymorphic display according to claim 1,wherein the electrolyte layer of at least one of the plurality of pixelsis pixelated.
 10. The polymorphic display according to claim 1, whereinone or more of the redox layers is a solid, semi-solid, or gel.
 11. Thepolymorphic display according to claim 1, wherein one or more of theredox layers is transparent, reflective, opaque or colored.
 12. Thepolymorphic display according to claim 1, wherein one or more of theelectrolyte layers is a solid, semi-solid or gel.
 13. The polymorphicdisplay according to claim 1, wherein one or more of the electrolytelayers is transparent, reflective, opaque or colored.
 14. Thepolymorphic display according to claim 1, wherein the redox layer of aset of pixels comprises a plurality of electropolymerizable monomers.15. The polymorphic display according to claim 14, wherein one or moreof the plurality of electropolymerizable monomers is configured as alayer.
 16. The polymorphic display according to claim 15, wherein thelayers of electropolymerizable monomers have distinct or overlappingshifted ranges of polymerization activation thresholds.
 17. Thepolymorphic display according to claim 1, wherein one or more of theredox layers comprise additives, microbeads or other fillers to form asolid, semi-solid or a gel structure.
 18. The polymorphic displayaccording to claim 1, wherein one or more of the electrolyte layerscomprise additives to form a solid, semi-solid or gel structure.
 19. Thepolymorphic display according to claim 18 wherein the additives includethermally curable or UV curable monomer.
 20. The polymorphic displayaccording to claim 1, wherein one or more of the redox layers isflexible, semi-rigid or rigid.
 21. The polymorphic display according toclaim 1, wherein one or more of the electrolyte layers is flexible,semi-rigid or rigid.
 22. The polymorphic display according to claim 1,wherein the polymorphic display is flexible, semi-rigid or rigid. 23.The polymorphic display according to claim 1, further comprising displaydriver circuitry.
 24. The polymorphic display according to claim 23,wherein the display driver circuitry includes a display driverintegrated circuit.
 25. The polymorphic display according to claim 23,wherein the display driver circuitry is configured to operate a signalprotocol.
 26. An intelligent display device comprising, a polymorphicdisplay, further comprising; a plurality of pixels, the plurality ofpixels each comprising a redox layer and an electrolyte, wherein theelectrolyte layer is configured adjacent to the redox layer; a first setof pixels from the plurality of pixels, the redox layer of all thepixels in the first set of pixels comprising a first redox material; asecond set of pixels from the plurality of pixels, the redox layer ofall the pixels in the second set of pixels comprising a second redoxmaterial, and wherein the operable properties of the pixels of the firstset of pixels and the pixels of the second set of pixels are determinedby their respective redox layers; a processor; a memory; and a powerapparatus.
 27. The intelligent display device according to claim 26,wherein the memory is constructed to store a signal protocol.
 28. Theintelligent display device according to claim 27, wherein the processoris configured to generate switching or maintenance signals according tothe signal protocol.
 29. The intelligent display device according toclaim 26, wherein the processor is configured to generate switching ormaintenance signals.
 30. The intelligent display device according toclaim 26, further comprising a communication apparatus.
 31. Anintelligent display device according to claim 26, further comprising asensor.
 32. An intelligent display device according to claim 26, furthercomprising an actuator.
 33. An intelligent display device according toclaim 26, further comprising a clock or timer.
 34. An electro-opticdisplay comprising, a plurality of pixels; the plurality of pixels eachcomprising a redox layer and an electrolyte layer, the electrolyte layerconfigured adjacent to the redox layer; a first set of pixels from theplurality of pixels, the redox layer of all the pixels in the first setof pixels comprising a first electropolymerizable monomer; a second setof pixels from the plurality of pixels, the redox layer of all thepixels in the second set of pixels comprising a secondelectropolymerizable monomer; and wherein the operable properties of thepixels of first set of pixels and the pixels of the second set of pixelsare the same, and the optical properties of the second set of pixels aredifferent as compared to the first set of pixels.
 35. The electro-opticdisplay according to claim 34, wherein the second electropolymerizablemonomer is the different compared to the first electropolymerizablemonomer.
 36. The electro-optic display according to claim 34, whereinthe second electropolymerizable monomer the same as the firstelectropolymerizable monomer.
 37. The electro-optic display according toclaim 36, further wherein the electrolyte layer of the second pixel setis different as compared to the electrolyte layer of the first set ofpixels.
 38. The electro-optic display according to claim 35, where theredox layer of a set of pixels comprises a plurality ofelectropolymerizable monomers.
 39. The electro-optic display accordingto claim 38, where one or more of the plurality of electropolymerizablemonomers is configured as a layer.
 40. An intelligent display devicecomprising, an electro-optic display further comprising, a plurality ofpixels; the plurality of pixels each comprising a redox layer and anelectrolyte layer, the electrolyte layer configured adjacent to theredox layer; a first set of pixels from the plurality of pixels, theredox layer of all the pixels in the first set of pixels comprising afirst electropolymerizable monomer; a second set of pixels from theplurality of pixels, the redox layer of all the pixels in the second setof pixels comprising a second electropolymerizable monomer, and whereinthe operable properties of the pixels of first set of pixels and thepixels of the second set of pixels are the same, and the opticalproperties of the second set of pixels are different as compared to thefirst set of pixels, a processor; a memory; and a power apparatus. 41.The intelligent display device according to claim 40, wherein the memoryis constructed to store a signal protocol.
 42. The intelligent displaydevice according to claim 41, wherein the processor is configured togenerate switching or maintenance signals according to the signalprotocol.
 43. The intelligent display device according to claim 40,wherein the processor is configured to generate switching or maintenancesignals.
 44. The intelligent display device according to claim 40,further comprising a communication apparatus.
 45. An intelligent displaydevice according to claim 40, further comprising a sensor.
 46. Anintelligent display device according to claim 40, further comprising anactuator.
 47. An intelligent display device according to claim 40,further comprising a clock or timer.